Mellow Mushroom is celebrating is 40th anniversary with special one-day prices from its original 1974 menu.

Locations nationwide will be offering a small cheese pizza for $2.50, Coke products for 30 cents, and Michelob, Budweiser or PBR for 75 cents.

Prices are good on Wednesday, Aug. 20 and are valid on dine-in meals only. Customers are limited to one small cheese pizza each.

Mellow Mushroom will also be hosting a contest for customers to win a trip to Amsterdam for two. Customers will be able to pose, in-store, with a backdrop of the first Mellow Mushroom location and post it to Instagram with #40YearsBaked to enter. Those without an Instagram account can upload their images to http://www.40yearsbaked.com.